Tool attachment



May 22, 1951 H. o. THOMPSON TOOL ATTACHMENT Filed June 13, 194'.7

Patented May 22, 1951 UNITED STATES PATENT OFFICE The present inventionrelates to improvements in tool attachments and its principal object isto provide a convenient means for attaching a tool such as a sandingwheelor a buffer to a portable electrical drill or similar instrument.

Portable drills of the character described are made in many differentforms, and usually cornprise a suitable housing having a motor, a drillchuck driven by the motor, and a handle for holding and directing thetool or instrument, the handle usually having a suitable switch controloperable by the thumb or one of the fingers of the operator.

The present invention is a further development of the tool attachmentdescribed and claimed in my co-pending application, Serial Number710,667, filed November 18, 1946, now abandoned.

In the latter invention it was proposed to provide a direct drivebetween the tool, such as a grinding wheel, and the chuck with asuitable guard surrounding the drive and the chuck to furnish a handlefor the operator and to protect the operator from injury.

In the present invention it is proposed to provide a right-angular driveso that the axis of the tool is disposed at a right angle to the axis ofthe chuck.

It is further proposed to provide a handle arranged at a right angle toboth the axes of the tool and the chuck so that the operator may holdthe drill handle in one hand and the attachment handle in the other handfor convenient manipulation and may also turn the tool with respect tothe chuck into any desired angular position.

It is further proposed to provide a suitable housing surrounding thedrive mechanism and a guard projecting from the housing over the chuckso as to protect the hands of the operator.

Further objects and advantages of my invention will appear as thespeciication proceeds, and the novel features of my invention will befully defined in the claims attached hereto.

The preferred form of my invention is illustrated in the accompanyingdrawing, in which Figure 1 shows my attachment as applied to a portableelectrical drill,

Figure 2, a vertical central section, on an enlarged scale, through theattachment and a portion of the drill, and

Figure 3, a plan view of the attachment.

While I have shown only the preferred form of my invention, I wish tohave it understood that various changes and modifications may be madewithin the scope of the claims attached hereto without departing fromthe spirit of the invention.

Referring to the drawing in detail, the electrical drill I may be of anysuitable form and is preferably made of light weight for convenienthandling by the operator. It is here shown as comprising a housing 2having a motor mounted therein, a handle 3 at the rear end of thehousing and having a thumb control switch 4 and a chuck 5 at the frontend of the housing, The chuck may be of 8 used as an anchoring memberfor a key (not shown), which is used for driving the operating member"I,

'I'he device thus far described is of conventional construction and noclaim of novelty is made for the same.

My invention comprises a suitable housing 9 having two tubularextensions l0 and Il arranged at a right angle to one another. A bushingI2 is threaded into the extension I0 and a bushing I3 is threaded intothe extension II. The bushing I2 has a shank I4 revolvable therein, andthis shank terminates in a reduced extension I5 adapted to be gripped bythe jaws 6 of the chuck. The forward end of the shank I Il extends intothe housing 9 and carries a bevelled gear I6, a suitable bearing I'Ibeing interposed between the bevelled gear and the bushing I2. Thel'atter bushing has a sleeve I8 projecting over the chuck to serve as aguard and this sleeve is formed with an aperture I9 to allow a key to beinserted into a hole 2|] of the anchoring member for operating themember I to tighten the jaws 6 of the chuck upon the end of the shankIll.

The bushing I3 carries a second shank 2l arranged at a right angle tothe shank I4 and the yinner end of this shank has a bevelled gear 22,inside the housing 9 to mesh with the bevelled gear I6. A bearing 23 isinterposed between the bevelled gear 22 and the inner end of the bushingI3. The outer end of the shank 2l carries a desired tool, such as asanding wheel 24, or a buffer, and is threaded as at 25 so that anysuitable make of tool may be attached thereto, either directly or bymeans of an adaptor.

The housing 9 has a handle 26 projecting therefrom, the handle beingpreferably straight and arranged at a right angle to both of the axes ofthe chuck and the tool.

The operation of the invention will be readily understood from theforegoing description. The

assaesc attachment forms an independent unit and may be easily securedupon the portable drill by introducing the end I5 of shank I4 into thechuck 5 and by tightening the chuck upon the shank by means of a keyintroduced through the hole I9. The attachment thus having been securedthe tool is ready for use, and upon turning on the switch 4 the sandingwheel 24 will be set into rapid rotation. The operator may grip thehandle 3 in one hand and the handle 26 in the other hand for guiding thesanding wheel over the surface to be sanded, and he may also turn theattach-ment about the axis of the chuck to any desired angularity foraccess to the Work lfrom above, from below and from any side and angledesired.

The tool is particularly adapted Vfor sanding and buiiing fiat andslightly curved surfaces such as automobile body and fender work.

I claim:

1. A tool attachment for a portable electric motor having a casing and arotary chuck projecting therefrom, the attachment comprising a housinghaving two tubular extensions arranged at a right angle to one another,a bushing threaded into one of the extensions and having a cylindricalguard projecting outwardly therefrom, the guard having a diameter larger.than that ofthe bushing and forming a shoulder therewith bearing on theend of the extension when the bushing is screwed in fully, the bushingbeing slightly longer than the extension so as to project inwardlybeyond the same when the shoulder-bears on the outer end of theextension, a shank revolvable in the bushing andhaving an outer endlocated Within the guard adapted -for gripping by the jaws of the chuckwhile the guard forms an enclosure for the chuck, a bevel gear on theinner' end of the shank Within the housing, a bearing interposed betweenthe bevel gear and the inner end of the bushing, a second bushingthreaded into the second extension and having a head bearing on theouter end of the extension and having an inner end projecting inwardlyof the inner end of the extension, a second shank revolvable in thesecond bushing and having a bevel gear Within the housing meshing withthe first gear and having a tool mounted on its outer end outside of thehousing, and a bearing interposed between the second bevel gear and theinner end of `.the'second bushing.

2. A tool attachment as deiined in claim l, in which rthe housing Vhas ahandle projecting therefrom radially with respect to the axis of the rstshank to facilitate manipulation of the housing about said axis.

HOWARD O. THOMPSON.

REFERENCES CITED The `following references are of record in the file ofthis patent:

UNITED STATES PATENTS Happe et al. Mar. 22,

